Air-heater for compressed-air engines.



H. W. SHONNARD & W. DIBTER. AIR HEATER POE COMPRESSED AIR ENGINES.

APPLIOATIOK FILED MAY 21, 1907.

927,434. Patented July 6,1909.

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Fig.1.

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. INVENTORS:

Mar-M V WM,

By Af/umqvx,

APPLICATION FILED MAY 21, 1907.

Patented July 6, 1909.

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INVENTORS:

UNITED STALIESMEAEENT OFFICE.

HAROLD W. SHONNARD, OF EAST ORANGE, NEW JERSEY, AN!) WILLIAM llll'l'llllt, 0]" NEW YORK, N. Y., ASSIGNORS TO E. W. BLISS COMPANY, OFllltUUhLYN, NEW YORK, A COR- PORATION OF WEST VIRGINIA.

AIR-HEATER FOR COMPRESSED-AIR ENGINES.

Specification of Letters Patent.

Patented ma 6, 1909.

Application filed May 2 1, 1907. Serial No. 374,824.

To all wlwm it may concem:

Be it known that we, HAROLD W. SHON- mmn, resid' in East Orange, in thecounty of Essex and tate of New Jersey, and WIL- LIAM Dm'rnn, residingin the borough of Brooklyn, county of Kings, city and State of New York,both citizens of the United States have jointly invented certain new anduseful Improvements in Air Heaters for Compressed-Air Engines, of whichthe following is a specification.

In utili compressed air as a source of ower it esirable to rovide meansfor eating the compressed air before admitting it to the engine, inorder to increase the energy of the engine and avoid the incon-'veniences attending the expansion of unheated compressed air. ThlSmethod is of especial importance in automobile torpedoes. For thispurpose, owing to the brief time available, the heating is necessarilycrformed by the burning of a fluid fuel sucli as alcohol or gasolenedirectlyin the com ressed air, so that the hot products of combustioneommingle with the heated air and flow to the engine. The heater orcombustion chamher is in some cases placed within the compressed airreservoir; in other cases it is ormed as an enlargement in the pi e orconduit leading from the reservoir to t e engine.

It is necessary to perform the ignition at the moment of launching thetorpedo, and substantially coincident with the admitting of air to startthe engine. Difficulty has been ex erienced in accomplishing theignition in t e powerful stream of com ressed air flowing through thecombustion chamber to the engine.

The object of our invention is to provide means for obviating thisdisadvantage.

According to our invention we provide special means for controlling theflow of air whereby the air is retained in a sufficiently quiescentcondition in the combustion chamber during the operation of the igniterto enable the ignition to be performed with certainty, and thereu on thefull normal flow of air is established t on h the chamber.

Our invention may e variously realized, but refcrabl the air is firstadmitted to the com ustion c amber upon the opening of the startingvalve, and is kept momentarily from flowing out therefrom, or itsoutflow is restricted to a relatively small volume; during thismomentary interval the introduction of liquid fuel into the chamber hascoinmcnced, and at the proper instant the igniter acts to va orize andignite the fuel, thereby filling t 1c chamber with llame; at the end ofthe momentary interval prescribed for insuring these operations, acontrolling valve or device automatically o acratcs to cause the fullflow of air to take p ace through the chamber.

Referring to the accompanying drawings,- Figure 1 is a fragmentarylongitudinal vertical section of the middle portion of an automobiletorpedo, showing one application of r invention thereto. Fig. 2 showsthe ombustion chamber and its related parts on a larger scale invertical mid-section. Fig. 3 isa fragmentary section of a modification.Figs. 4 and 5 are views similar to Fig. 2, illustrating modifications.Fig. 6 is an enlarged fragment of Fig. 2, showing in section a suitableconstruction of automatic i 'niters.

Referring first to Fig. 1, let A csignate the torpedo hull or shell, Bthe compressed air reservoir, 0 the engine, which in this instance isshown as a turbine, and l) the propeller shaft driven by the engine andextending aft for driving the propeller screws. The compressed air assesfrom the reservoir B to the engine t irough a conduit E E, whichcomprises a pipe a leading from the usual filling and stop valve F toany suitable starting valve G, a pipe 6 leading thence to any suitablepressure-reducing valve H, a pipe 6 leading thence to the combustionchamber or so-oalled superheater J, and the pipe (1 leading thence tothe nozzle or inlet of the turbine. The valves referred to may be of anyusual or suitable construction, and the chamber J may be otherwiselocated. K is the receptacle for liquid fuel, commonly called the fuelot; a is a ipe admitting compressed air t ereto from t 1e ipc c, and fis a pipe for conveying the liquid fuel therefrom to the atomizing orspraying nozzle 9 or otherwise into the chamber J; h is any suitablevalve or obstruction for controlling the flow of air to the chamber Jand thereby dctermining the rate of introduction of the fuel; L is theigniter of any suitable construction. So far as described there is nonovcity in the parts referred to.

In the normal operation of such apparatus,

upon the launching of the torpedo the starting valve (i is mitomaticallyopened, where by air is admitted to the reducer H which lowers itsn'essure and admits it through the chamber J directly to the engine. Aportion of the air flowing through the by-pass or shunt e expels thealcohol or other fluid from the reservoir K, and introduces it into thechamber J in a spray or otherwise; this result occurs almost.instantaneously upon the admission of air, and at the proper instant theigniter 11 operates to direct a flame into the chamber .l and intocontact with the entering l'uel so as to ignite the same. The ignitingoperal ion should be instantaneous, and, the ignition once eliected, thecombustion should maintain itself with such intensity that the powerfulstream or blast of compressed air flowing through the combustion chamberwill not blow out the flame. The air flowing to the engine is thushighly heated, and its volume augmented by the admixture with it of thegaseous products of combustion.

It has been found in practical use oi such a combination of apparatusthat the ignition is not accomplished with certainty, and under someconditions it is extremely dillicult to eliect the ignition at all. Thiswe explain upon the theory that the powerful stream of compressed airblowing through the combustion chamber prevents the flame from theigniter accom lishing the vaporiza tion of the liquid fuel alcohol) andits ignition so is to generate heat enough to maintain the vaporizationand ignition of the fuel which continues to enter; or it may be that theblast is so powerful that it blows out the flame before the combustionbecomes fierce enough to maintain and propagate the flame at a morerapid rate than the flow of the air.

Proceeding upon the theory that it is the too powerful current, of airwhich defeats the requisite certainty in ignition, our invention seeksto check or even arrest the flow of air, so as to maintain the airwithin the combustion chamber sufiiciently quiescent, and for asufiicient duration of time, to insure the ignition of the fuel. Thecombustion once instituted, it is necessary, in order to maintain it, tointroduce air in large volume, or propertionally to the rate ofintroduction of the fuel; accordingly we provide that after the momentarretardation which insures the ignition, t e full or a sufiicient flow ofair shall be directed through the combustion chamber.

The construction shown best in Fig. 2 is adapted to carry our inventioninto effect. The outlet 1', from the chamber J is primarily closed by avalve M which is held to its seat by a catch P engaging the valve stem.The valve has preferably a groove or leak-opening which will permit asmall stream of air to flow through before the valve opens, for thepurpose primarily of genlly starting the engine in advance of the fullrush of air, and secondarily 01' causing a limited How of air to passthrough the combustion chamber to insure a supply of oxygen to the flameduring the briel interval between the ignition and the opening of thevalve M.

For opening the valve M provision is made for automatically withdrawingthe catch P at the end of a brief interval of timel'ollowing thepreliminaryadmission of air. For this purpose a restricted duct k isprovided rceeiving compressed air from the chamber J or other source,and admitting it to a chamher I in which works the piston or plunger mof the catch 1. When the starting valve G is opened at launching, theair is instantly admitted through the reducing valve 11 to thecombustion chamber J, which it instantly fills with compressed air, andthen ensues a brief delay while the air is flowing out through the ductIc into the chamber 1 until it attains enough pressure therein toovercome the tress of the spring p, whereupon it forces back the catchI, and the valve M instantly flies open and permits the full outflow tooccur through the combustion chamber to the engine. The brief delay thusinvolved afl'ords the momentary retardation which insures the successfulignition. The igniter L is constructed to operate suflicicntly inadvance of the catch P to take advantage of the approximate quiescencedue to the momentary retardation or imprisonment of the air.

For automatically resetting the valve M after the operation, it may beprovided with a spring 9, which, when the run is over and the airpressure has blown itself out, will lift the valve back against theseat, where it is again caught and held by the catch P.

The igniter L might be an electric igniter, but is preferably an igniterof the pistol type which is operated by the admission of compressed air,and ignites a cartridge, the burning of which projects the ignitingflame into the chamber J. The construction of the iguiter, however,forms no part of our invention, it being only requisite that it shall beadapted to operate at the proper instant and before the opening of thevalve M.

A suitable construction of the igniter is shown in Fig. 6, where a spri-pressed plunger or hammer t is restrained y a scar a carried by aspring-pressed piston 1). Upon the first admission of compressed air tothe chamber J the air enters the shell of the igniter (through anysuitable o ning, as a. duct 'w for exam 1e) and forces ack the piston o,thereby re easing the hammer t which I is pirojected by its spring sothat its end stri es a percussion cap a: and ignites the cartridge y.

Fig. 3 illustrates a modification wherein the valve M is substituted bya thermic device which adapted to open and admit the low of air onlyupon the completion of the ignition. A l'usible disk Q is placed in theoutlet from the chamber J, being preferably formed with a small hole 35through it for the same purpose as the hole in the valvelvl. The outflowof air through this hole carries the flame to it as soon as the ignitionoccurs, so that the fusible disk is quickly melted and carried out ofthe heater, leaving the full outlet opening. If made of vaporizablematerial it is permitted to simply blow out through the engine withoutharm, but otherwise its particles may be caught centrilu gally inpockets 1' r. Of course a new fusible disk must be applied before thenext operation.

Our invention may be variously otherwise modified without departing fromits essential features. For example, it is not essential that thecombustion chamber be located in the sole conduit from the reservoir tothe engine, as a by-pass might be arran ed around the chamber to conveythe air at iirst to start the engine, and upon accomplishing theignition a valve might be operated to direct the main flow through thecombustion chamber. This is shown in Fig. 4, where P is the by-pass, andM is the valve, which may be operated by the same means as the valve Min Fig. 2. At starting, the valve is closed to the combustion chamber J,but a small vent s admits a sullicient flow of air to start thecombustion. Or the combustion chamber proper might be within anotherchamber so that the air would be distributed uniformly around thecombustion chamber in such manner that an eddy current would enter suchchamber, so that the air in the combustion chamber pro er would be heldsufliciently quiescent during the ignition, while after ignltion theeddy current would supply sufficient oxygen to maintain combustion. Thisis shown in Fig. 5, where J is the inner chamber and J the outerchamber.

Our invention is even applicable with a combustion chamber which islocated within the main reservoir.

Our invention is chiefly useful where the propelling engine is of theturbine type, and where the combustion chamber is introduced in the mainconduit from the reservoir to the engine, or in a branch thereof.

\Ve make herein no specific claim to the constructions shown in Figs. 4and 5, the same being specifically claimed in our divisional applicationfiled February 8, 1909, Serial No. 476,785.

We claim as our invention:-

1. The combination of a compressed air reservoir, an engine, a conduitleading from the reservoir to the engine, a combustion chamber incommunication with said conduit, means for feeding fluid fuel into saidchamber during the run of the engine, means for igniting it therein uponthe starting of the engine, and automatic means for momentarily holdingback the flow of air through said chamber during the operation of theigniting means to insure the ignition.

2. In an automobile torpedo, the combination of a compressed airreservoir. an engine, a conduit leading from the reservoir to theengine, a combustion chamber in communication with said conduit, meansfor feeding fluid fuel into said chamber during the run of the torpedo,means for igniting it therein upon the launching of the torpedo, astarting valve, and autom atic means adapted upon the admission ofcompressed air to said chamber to retain it there momentarily during theignition, and then to release it and permit a full flow of air throughthe chamber.

3. In an automobile torpedo, the combination of a compressed airreservoir, an engine, a conduit leading from the reservoir to theengine, a combustion chamber in communication with said conduit, meansfor feeding fluid fuel into said chamber during the run of the torpedo,means for igniting it therein upon the launching of the torpedo, astarting valve, and an automatic valve at the outlet from the combustionchamber adapted to momentarily retain the compressed air therein duringthe ignition.

In Witness whereof, we have hereunto signed our names in the presence oftwo subscribing witnesses.

HAROLD W. SHONNA'RD. WILLIAM DIETER.

Witnesses:

C. R. GABRIEL, H. C. SEAMAN.

